/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.handler.codec.http2;

import static io.netty.handler.codec.http2.Http2FrameLogger.Direction.OUTBOUND;
import static io.netty.util.internal.ObjectUtil.checkNotNull;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.util.internal.UnstableApi;
import io.prometheus.client.Histogram;
import org.tikv.common.util.HistogramUtils;

/**
 * Decorator around a {@link Http2FrameWriter} that logs all outbound frames before calling the
 * writer.
 */
@UnstableApi
public class Http2OutboundFrameLogger implements Http2FrameWriter {
  private final Http2FrameWriter writer;
  private final Http2FrameLogger logger;

  public static final Histogram writeHeaderLogDuration =
      HistogramUtils.buildDuration()
          .name("netty_http2_write_header_log_duration_seconds")
          .help("HTTP/2 write header log duration in seconds")
          .register();

  public Http2OutboundFrameLogger(Http2FrameWriter writer, Http2FrameLogger logger) {
    this.writer = checkNotNull(writer, "writer");
    this.logger = checkNotNull(logger, "logger");
  }

  @Override
  public ChannelFuture writeData(
      ChannelHandlerContext ctx,
      int streamId,
      ByteBuf data,
      int padding,
      boolean endStream,
      ChannelPromise promise) {
    logger.logData(OUTBOUND, ctx, streamId, data, padding, endStream);
    return writer.writeData(ctx, streamId, data, padding, endStream, promise);
  }

  @Override
  public ChannelFuture writeHeaders(
      ChannelHandlerContext ctx,
      int streamId,
      Http2Headers headers,
      int padding,
      boolean endStream,
      ChannelPromise promise) {
    Histogram.Timer logTimer = writeHeaderLogDuration.startTimer();
    logger.logHeaders(OUTBOUND, ctx, streamId, headers, padding, endStream);
    logTimer.observeDuration();
    return writer.writeHeaders(ctx, streamId, headers, padding, endStream, promise);
  }

  @Override
  public ChannelFuture writeHeaders(
      ChannelHandlerContext ctx,
      int streamId,
      Http2Headers headers,
      int streamDependency,
      short weight,
      boolean exclusive,
      int padding,
      boolean endStream,
      ChannelPromise promise) {
    Histogram.Timer logTimer = writeHeaderLogDuration.startTimer();
    logger.logHeaders(
        OUTBOUND, ctx, streamId, headers, streamDependency, weight, exclusive, padding, endStream);
    logTimer.observeDuration();
    return writer.writeHeaders(
        ctx, streamId, headers, streamDependency, weight, exclusive, padding, endStream, promise);
  }

  @Override
  public ChannelFuture writePriority(
      ChannelHandlerContext ctx,
      int streamId,
      int streamDependency,
      short weight,
      boolean exclusive,
      ChannelPromise promise) {
    logger.logPriority(OUTBOUND, ctx, streamId, streamDependency, weight, exclusive);
    return writer.writePriority(ctx, streamId, streamDependency, weight, exclusive, promise);
  }

  @Override
  public ChannelFuture writeRstStream(
      ChannelHandlerContext ctx, int streamId, long errorCode, ChannelPromise promise) {
    logger.logRstStream(OUTBOUND, ctx, streamId, errorCode);
    return writer.writeRstStream(ctx, streamId, errorCode, promise);
  }

  @Override
  public ChannelFuture writeSettings(
      ChannelHandlerContext ctx, Http2Settings settings, ChannelPromise promise) {
    logger.logSettings(OUTBOUND, ctx, settings);
    return writer.writeSettings(ctx, settings, promise);
  }

  @Override
  public ChannelFuture writeSettingsAck(ChannelHandlerContext ctx, ChannelPromise promise) {
    logger.logSettingsAck(OUTBOUND, ctx);
    return writer.writeSettingsAck(ctx, promise);
  }

  @Override
  public ChannelFuture writePing(
      ChannelHandlerContext ctx, boolean ack, long data, ChannelPromise promise) {
    if (ack) {
      logger.logPingAck(OUTBOUND, ctx, data);
    } else {
      logger.logPing(OUTBOUND, ctx, data);
    }
    return writer.writePing(ctx, ack, data, promise);
  }

  @Override
  public ChannelFuture writePushPromise(
      ChannelHandlerContext ctx,
      int streamId,
      int promisedStreamId,
      Http2Headers headers,
      int padding,
      ChannelPromise promise) {
    logger.logPushPromise(OUTBOUND, ctx, streamId, promisedStreamId, headers, padding);
    return writer.writePushPromise(ctx, streamId, promisedStreamId, headers, padding, promise);
  }

  @Override
  public ChannelFuture writeGoAway(
      ChannelHandlerContext ctx,
      int lastStreamId,
      long errorCode,
      ByteBuf debugData,
      ChannelPromise promise) {
    logger.logGoAway(OUTBOUND, ctx, lastStreamId, errorCode, debugData);
    return writer.writeGoAway(ctx, lastStreamId, errorCode, debugData, promise);
  }

  @Override
  public ChannelFuture writeWindowUpdate(
      ChannelHandlerContext ctx, int streamId, int windowSizeIncrement, ChannelPromise promise) {
    logger.logWindowsUpdate(OUTBOUND, ctx, streamId, windowSizeIncrement);
    return writer.writeWindowUpdate(ctx, streamId, windowSizeIncrement, promise);
  }

  @Override
  public ChannelFuture writeFrame(
      ChannelHandlerContext ctx,
      byte frameType,
      int streamId,
      Http2Flags flags,
      ByteBuf payload,
      ChannelPromise promise) {
    logger.logUnknownFrame(OUTBOUND, ctx, frameType, streamId, flags, payload);
    return writer.writeFrame(ctx, frameType, streamId, flags, payload, promise);
  }

  @Override
  public void close() {
    writer.close();
  }

  @Override
  public Configuration configuration() {
    return writer.configuration();
  }
}
